Apparatus for applying paint



Nov. 27, 1934. A. F. JENKINS 1,982,055

APPARATUSFOR APPLYING PAINT v Filed Feb. lS, 1931 S'Sheets-Sheeit lI Nov. 27, 1934. A. FQ JENklNs 1,982,055

APPARATUS FOR APPLYING PAINT Filed Feb. 18, 1931 3 Sheets-Sheet 2 5. ,I fi,

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Nov. 27, 1934. A. F. JENKINS APPARATUS FOR APPLYING PAINT Filed Feb. 18, 1931 3 Sheets-Sheet 3 Patented Nov. 27, 1934 UNITED l STATES PATENT OFFICE 16 Claims.

This invention relates to spray guns for paint or similar coating material and more particularly to the type of spray gun, or so-called air brush, in which auxiliary jets of compressed air are employed to alter the shape of the spray of coating material impelled by the main air blast.

The general object of the invention is the provision of a novel and improved spray gun which is capable of more accurate operation than the usual device of this type and one in which the air supply to both the impelling and the modifying jets may be readily controlled.

Another object of the invention is to provide a spray gun of this type which embodies certain features of construction by which the ease and economy of manufacture are appreciably increased.

One feature of the invention, whereby greater accuracy and evenness of outline of the spray of coating material is obtained, is the improved construction of the nozzle of the spray gun, particularly with reference to the manner of drilling and forming the portions -thereof through which issuev the supplemental jets. A

Another highly important feature of. the invention is the provision of a novel air controlling valve by means of which the supply of air may not only be cut off entirely from both the main and supplemental jets but the quantity or pressure of the initial air supplied to the valve chamber and of that issuing from said chamber to both jets may be varied at will.

Other objects and features of novelty will be apparent from the following specification when read in connection with the accompanying drawings in which one embodiment of the invention is illustrated by way of example.

In the drawings:

Figure 1 is a side elevational view,partly invertical longitudinal section, of a spray gun or air brush forming one embodiment of my invention;

Figure 2 is a view in rear elevation of a portion of the nozzle of the spray gun;

Figure 3 is a transverse sectional view taken on line 3--3 of Figure 1;

Figure 4 is a fragmentary top plan view of the rear body portion of the spray gun;

Figure 5 is a transverse cross sectional view taken on line 5-5 of Figure 1;

Figure 6 is a view in side elevation of the body portion of the air valve; Y

Figures 7, 8, and 9 are transverse sectional views thereof taken on lines 'Lv-7, 8-8, and 9 9, respectively, of Figure 6;

Figure 10 is a diagram illustrating the operation of the air valve;

Figure 11 is a view similar to Figure 1, showing the body portion of another form of my improved spray gun; and

Figure 12 is a fragmentary sectional view taken on line 12--12 of Figure 11.

The spray gun designated generally by the numeral 10 in Figure 1 comprises the forward body portion 11, which is adapted to carry the 65, spray nozzle and its associated parts, the rear body portion 12, which is adapted to house the air controlling valve and the operating mechanism for fthe coating material valve, the upper connecting portion 13 through which the air pas- 7"0l y sages to the nozzle are adapted to pass, and the lower connecting portion 14. Any suitably designed handle or grip 15 may be provided, and the ring or eye 16 is formed upon the upper portion of the spray gun for the purpose of provid- 75 ing means whereby the gun may be suspended from a suitable support when not in use.

At the lowermost point of the forward body portion l11 there is provided the boss 20 which is interiorly threaded as at 21 for the attach- 80 ment of suitable connections leading to the supply of paint or other coating material. From this boss the passageway 22 leads to the central coating material chamber 23 into the open forward end of which is threaded the coating material 85 nozzle member 25. The forwardly projecting portion of -the nozzle member 25 is generally conical in shape and this member is provided with the bore 26 which is tapered to form the restricted forward orifice 2'1. As a means for 90 controlling the flow of coating fluid through the orifice 27 the tapered needle valve 28 is provided and is adapted to reciprocate longitudinally within the central bore of the member 25 and to be carried by the valve stem 29which projects rear- 95 wardly from the forward body portion 11 of the gun through the bore 30, packing 31, and packing nut 32. The valve stem 29 is actuated by means disposed within the rear body portion 12 which will be later described.

The coating material nozzle member 25 is provided with the radially extending flange which is` adapted to overlie the front face of the body portion 11 and is provided with a circular series of spaced perforations 36 which are connected at 105 their rearwardly disposed ends by the annular groove 37 which is adapted to provide communication between these orices 36 and the compressed air passageway 40 which passes through the upper connecting portion 13 of the spray 110 gun. By this means the 'main air supply for im-k pelling the paint spray is conducted to the chamber 41 formed within the nozzle head 42. The nozzle head 42 is adapted to surround the paint supply nozzle and is adapted to fit snugly around the outer periphery of the flange 35.

Centrally of the forward wall of the nozzlev head 42 there is provided an aperture 45 which surrounds the restricted forward end of the paint nozzle member 25 so as to provide an annular opening 46 through which the main air jet is adapted to flow so as to draw the paint supply through the oriilce 27 when the needleyalve 28 is opened. 'I'he nozzle head 42 is, retained in which is adapted to be threaded upon the for- Upon the forward end of the nozzle head 42 there are formed the diametrically oppositely disposed raised portions or projections 53 which are provided with the inner converging faces 54.

Within they confines of the collar member 48, theA head 42 is provided with the annular surface 55 which is parallel with the surfaces 54 formed on the projections 53. Each of the projections 53 ,l y

'limits along the stem 75 and thereby to permit is provided with the passageways 56 which are drilled through the `projections so that their axes are respectively perpendicular to the vsur-- faces 54 and. 55. It will be readily understood 4that the auxiliary air supply from the chamber 50 will be directed through the'converging passageways 56 and will impinge upon the circular spray provided by the central jet orifice 27,46 and serve to flatten the jet of sprayed material in the manner desired for certain kinds of work. The provision of paralleLsurfaces connected by the perpendicular passageways 56 isl an important feature of the present invention. `This feature not only assists in facilitating the operation of drilling, but also providesa passageway, the length of all. sides of which are equal. This "eliminates the presence of a' greater degree of yto frictionto which the air would be subjected in passing along the longer side of the passage and the consequent unevenness of the jet issuing 'from the supplemental passageway.

The nozzle head 42 is providedwith theradial flange 60, the outer periphery of' which is adapted to contact the inner surface of the collar 48 as at 61. This flange 60 is provided with the holes 62 at spaced intervals around its periphery for the passage of the air through 'the chamber 50. The inner end of the nozzle head 42 is provided with the radial flange 63 which is adapted to cover the annular groove 64 -formed in the front face of the body member 11. The flange 63 is also provided with the holes 65 which may be disposed in the same angular relation as the holes 62 in I the bushing 71.

the flange 60 as shown in Figure 2 of the drawings. Thus it will be seen that -the supplemental air supply passes throughv the passageway 51. groove 64, holes 65 and. 62. chamber 50 and passageways 56 from which it' issues in the form of auxiliary air jetsfor flattening the spray.

The rear body portion 12 is provided with the longitudinal bore 70 wherein is rigidly secured Threaded into the rear end of the bushing vas at 72 is the nut 73, sockets 74 being provided therein for the reception 0f im l cate within the central bore of the nut 73.

position by means of the lock nut'vor collar 48 .of the orifice 95.

appropriate tool for applying and removing the same. 'I'he enlarged rearward portion 75 of the needle valve stem 29 is adapted to recipro- In order to continually urge the needle valve 28 toward its forward closed position within the nozzle member 25, an abutment 76 is rigidly secured to the stem 75 and a coil spring 77 is adapted to be compressed between the abutment 76 and the forward end of the nut 73. An adjustable cylindrical abutment 78 is threaded upon the enlarged valve stem portion 75 and is provided with a flat surface '79 which is adapted to cooperate with a correspondingly flattened interior portion 80 of the bushing 71 so as to prevent rotation of the abutment 78.

The abutment 78 is adapted to be engagedby the yoke 81 which is pivoted as at 82`upon an intermediate portion of the trigger 83.v A rearwardly extending lever 84 is formed upon the yoke 81 for manipulation preferably by the thumb of the operator to release the yoke 81 from its operative position wherein it is adapted to straddle the valve stem 29, 75. The trigger 83 is pivoted to an upper portion of the spray gun as at 85. 'In order to adjust the yoke contacting abutment 78 along the valve stem it is only necessary to rotate the stem portion 75 by manipulating thev knurled handle 87 at the rearmost end thereof whereupon the threadedvl abutment '78 may be moved to any desired position within certain leading from a source of pressure fluid such as lg compressed air. The interior of the boss 92 communicates with the chamber or bore by means of the forward portion of the bore 90 are the passageways l96 and 97 which communicate respectively with the passageways 40 and 51 which pass through the connecting portion 13 of the body member to the nozzle. It will be understood that the passageway 96 provides communication with the main central spray nozzle and that the passageway 97 provides communication with the supplemental wing jets 56.

The valve body lmember or casing 91 is provided with four separate stepped portions of different diameter, the largest and rearmost portion adapted to enclose the inlet air chamber 98, the two intermediate portions adapted to enclose Leading from the upper wall the outlet air chamber 99 and the smallest forward portion adapted to close the forward en d of the bore 90 as at 100. 'I'he rear end of the valve ca sing 91l is adapted to be closed by the tlireaded cap 102 and the inlet chamber 98 and the outlet chamber 99 are separated by the valve .seat 103, the orifice -of which is adapted to be controlled by valve body member 104, preferably being in the form of a spherical stainless steel ball, the packing nut 106 at the forward end ofthe valve chamber and to be actuated bycontact Valvestem 105 is adapted to pass through with the yoke 107 carried by the trigger 83 to raise the valve 104 from its seat against the 'pressure of the coil spring- 108 which is adapted to 'be retained by the cap 102. stood that the actuation of the valve 104 will permit the air to pass from the inlet chamber 98 of the valve to the outlet chamber 99 and thence to the nozzle. l

In order to control the quantity of air owing into the' inlet chamber 98 through the passageway 95 and from the outlet chamber 99 to the passageways 96 and 97, the valve body or casing 91 is rotatable within the body 90 and is provided with the apertures 110, 111, and 112, which communicate respectively with the passageways 95, 96, and 97. The valve body or casing 91 is continuously urged forwardly within the bore 90 by means of the coil spring' 115 which is adapted to be compressed between the cap 102 and the nut 116 which is threaded within the rear end of the bore 90. A stem 118 rigidly secured at its forward end to the cap 102 extends rearwardly through an aperture in the closure 116 and is provided at its rear end with the knurled nut or handle 120 which is secured to the stem 118 as, for example, by means of the set screw 121. The closure nut 116 may be provided with a circular series of sockets 122 for the insertion of a suitable tool for applying and removing the nut but during operation of the gun the forwardly extending flange 123 of the handle nut 120 is adapted to entirely cover the closure nut 116 and to abut the body portion 12 as at 124. As clearly shown in Figure 4 of the drawings, the periphery of the member 120 is graduated as at 125 so that the rotated position of the valve body 91. may be knownat any time by referring the graduations 125 to the arrow 126 on the body portion 12.

v In order to gradually throttle or diminish the' flow of air into the inlet chamber 98 and also from the outlet chamber'99 into the passageways 96 and 97, the tapering grooves 130, 131, and 132 are provided in the outer walls of the valve casing 91 so as to intersect the orices 110, 111, 112, respectively. The arrangement of these grooves and orices is most clearly shown in Figures 6-10 way 97. Therespective points at which these orifices begin to register with their respective pasl sageways is diagrammatically illustrated in Figure 10 of the drawings which has not been drawn to scale, the sizes of the openings and other dimensions being merely exemplary and not limiting in any sense. In this figure, the transverse sections through'the several grooves and orices have been projected in linear form rather than in circumferential and the point of maximum flow through the orifice 110 has been displaced through 90 so that it coincides with the points of maximum flow through the orifices 111 and 112 and are indicated by the legend maximum. The points of successive initial registry of the margins of the orifices with their respective passageways are indicated by the letters A, B, and C. Thel grooves 130, 131, and 132 are so arranged that through a 111, 112) to a, minimum as indicated in the dia- It will be undergram of Figure 1o at which point-there is stm extreme right hand portion of Figure 10, the sup- A ply of air to the wing jets is cut off and the inlet air supply and main nozzle jet supply increases from the minimum to the maximum. The line D in Figure 10 represents substantially the point at which a maximum round spray may be obtained, the supply of air to the wing jets being cut oif at this point. As already indicated, any desired condition of flow to the main and wing jets may be obtained by rotating the valve body 91 by manipulating the nut 120 with reference to the positionfof the graduations 125 thereon. In Figure 4 of the drawings, the nut 120 is shown in its zero position, that is, in the position it occupies with reference to the arrow 126 when the ports of the three-way air valve are in full registry with the corresponding` inlet and outlet passageways of the' spray gun. From this initial position, the nut may be turnedin a direction to ob,- tain either a flat or a round spray. In the embodiment illustratedthe portion of the scale 125 which must register with the arrow 126 to secure a round spray is indicated by the arrow marked R and the scale portion indicated by the arrow designated by theletter F must register with the arrow 126 when a flat spray is to be obtained. In other' words, the rotation of the nut 120 in the clockwise direction gives aY at spray and in the counter-clockwise direction gives a round spray.

It will also be understood that when the valve is set to supply the desired ow of air, the cut-off valve 104 is opened by manipulation of the trigger 83 and then in the proper sequence determined by the adjustment of the needle valve nut 87, the needle valve 28 is opened, supplying coating iiuid to the nozzle whereupon it is sprayed upon the work by the air jets which have preferably already come into operation.

Although the grooves have been illustrated and described as having their minimum depths at points three-quarters of the way through the cycle of adjustment of the valve, it is to be understood that these points can be located at varying distances from the apertures as desired.

In the embodiment illustrated in Figures 11 and 12 of the drawings, the body ofthe spray gun is formed by die-casting a suitable metal around certain machined parts and other inserts. This embodiment is of the same general shape as the form illustrated in Figure 1 comprising the fored to receive a three-way valve member similar in all respects to the valve 91 illustrated in Figure 1 of the drawings. These elements are adapted to be connected by the tubes 148 and 149 which are made of copper or other suitable material and are connected vto the inserts 146 and 147 by having their forward ends brazed into the sockets 150 and 151 in the nozzle receiving member retaining collar 48 which is illustrated in Figure 1. 'Ihe member 146 is interiorly threaded as at 157 for the reception of the coating material nozzle member and the chamber 158 is formed within the member 146 for the 'reception of coating material through a suitable passageway, the general location of which is indicated by the b roken lines at 159 leading to the boss 160 and which may be formed in any suitable manner 'such as by drilling or being coredv out during the casting process. A restricted bore 161 is provided in the machined part -146 'for guiding the needle valve stem controlling the flow of coating material through the nozzle. A threaded chamber 162 is providedin the rearward portion of the member 146 for the reception lof packing elements such as designated by the numerals 31 and 32 in Figure l.

The interio of the bushing 147 is shaped exactly -like the recess 90 provided in the spray gun 10 illustrated in Figure l, having the four stepped portions corresponding to the similarly stepped surfaces of the. valve 91 and also being provided with the inlet passageway 164 corresponding tothe passageway 95 shown in Figure 1.

Through the lower part of the rearward body portion l4lther is provided the bore 166 which is adapted to receive the needle valve actuating mechanism which is similar in mostrespects to v the mechanism already described with reference to the first embodiment of the invention. The

needle valve operating mechanism in this latter case, howeverf-differs-in the following respect from the formel-embodiment. The bushing'll having the flattened wall portion 79 is dispensed with and, in its stead, the rearward part of the lower connecting portion 143 is provided with the boss 168 provided with the flat upper surface 170. This'boss performs the same function asthe sleeve or bushing 7l in preventing the adjustable abutment 78 fromv rotating upon. the needle valve stem 25 during adjustment thereof, by means of the cooperation of the flattened surface 80`on the abutment {18 and the surface 170 on the boss 168. l

It will be understood that by means of the present invention, there has been provided a spray gun which affords a wider range of usefulness in permitting a more accurate control of atomization in delivering fluid in proportions regulated according to the needsof the operation being performed and' the materials used. Also, one vof the important features of the present device is that practically any source of impelling fluid may be used regardless of whether the pressure thereof exceeds that required for the particular operation to be performed, by means of a suitable construction and adjustment of the throttling valve of the gun, thus eliminating the ne cessity of the employment o f reducing valves or regulators in these situations. It will also be perceived that the graduation of the grooves in the three-way air valve prevents an undesirable modifications may be made in the embodiment illustrated and described herein without departing from the scope of the invention as defined in the following claims. i

Having thus described the invention, what claimed Yas new and desired to be secured by Letters Patent is: L

1. In a spraying device for coating material, in combination, a body portion, a nozzle provided with a coating material orifice, an associated propelling fluid orifice, and a supplemental fluid orifice for providing a spray modifying jet, means for controlling the supply of coating material to said nozzle, and a valve for controlling the supply of pressure fluid to said nozzle comprising a casing adapted to be adjustably secured within a recess formed in said body portion, a chamber within said casing, avalve seat and associated valve body member adapted to divide said chamber into an inlet portion and-an outlet portion, separate passageways leading from the pressure fiuid orifices` in said nozzle and opening into said recess, a passageway leading from a pressure fluid connection and opening into said recess, said casingv being provided with an aperture communicating with said inlet portion of the valve chamber and registerable with said last'V named passageway opening, and with two apertures communicatingv with said outlet portion and each registerable with the opening of one of vthe passageways leading to the nozzle, means associated with each of said 4apertures for throttling the iiow of fluid therethrough upon adjustment of said valve.

2. A spraying device as set forth in claim l in which means are provided for rotating said valve within said recess to effect said throttling of the pressure fluid.

3. A spraying device as set forthin claim 1 in which the valve casing apertures are of such size Iand. disposition with'respect to each other as to 115 and disposition with respect to each other as to register with their cooperating passageway openings in the following orderz--the inlet aperture,

' the outlet aperture communicating to the impelling orifice ofthe nozzle, and finally the outlet aperture communicating with the supplemental spray modifying jet.

5. A spraying device as set forth in claim r1 in which the throttling means of all of the apertures are adapted to proportionately reduce the flow of lfluid therethrough from a maximum to a minimumA during a portion of the adjusting movement of the valve and during the remaining portion of said movement the throttlinglmeans associated with said supplemental jet passageway is adapted to cut oil?v the flow through its aperture and the other two throttling means are adapted to increase the iiow of fluid through their associated apertures from a minimum to a maximum.

6. In a spraying device-for coating material, in combination, a body, portion, a nozzle provided 140 with a coating material orifice, an associated propelling fluid orifice, and a supplemental fluid orifice for providing a spray modifying jet. means for controlling the supply of coating material to said nozzle, and a valve for controlling the supply of pressure fluid to saidnozzle comprising'a casing adapted torbe adjustably securedv within a recess formed in saidbody portion,'a chamber n within said casing, a valve seat and associated valve body member adapted todivide said chamber into an inlet portion and an outlet portion, separate passageways leading from the pressure uid orices in said nozzle and opening into said recess, a passageway leading froma pressure uid connection and opening into said recess, said casing being provided with an aperture communicating with said inlet portion of the valve chamber and registerable with said last named passageway opening, and with two apertures communicating with said outlet portion and each registerable with the opening of one of the passageways leading to the nozzle, peripheral grooves formed in the outer surface of said casing, each of said grooves intersecting one of said apertures and being of a graduated depth whereby they pressure and flow of iluid through said apertures and corresponding passageways may be regulated by'rotative adjustment of said valve within said recess to present dierent portions of said grooves to said passageway openings.

7. A spraying device as set forth in claim 6 in which the maximum depths of said grooves occur adjacent their associated apertures and progressively and proportionately increase vin depth around a portion of the circumference of said valve whereupon the groove associated with the aperture adapted to communicate with the supplemental spray modifying nozzle jet ends, and the other two grooves for the remainder of the circumference of said valve progressively and proportionately increase in depth.

8. In a spray gun for applying coating material or the like, a valve actuating mechanism comprising a valve stem, a trigger, and operative connections between said stem and said trigger, comprising an adjustable abutment member carried by said stem and a boss formed upon a portion of said gun adapted to cooperate with a portion of said abutment member to prevent the rotation of said member especially during adjustment thereof.

9. In a spray gun for applying coating material or the like, a valve actuating mechanism comprising a valve stem, a trigger, and operative connections between said stem and said trigger, comprising an adjustable abutment member carried by said stem, and a bushing secured within said body portion and having a attened interior wall portion, a correspondingly flattened portion on said abutment member adapted to cooperate therewith to prevent the rotation of said member especially during adjustment thereof.

l0. In a spraying device for coating material or the like, in combination, a nozzle provided with coating material and pressure fluid oriiices, means for controlling the supply of coating material tov said nozzle, and a cartridge-like valve assembly for controlling the supply of pressure fluid to said nozzle, said assembly having a valve chamber therein, a valve seat and associated valve body member within said chamber adapted to divide said chamber into an inlet portion and an outlet portion, and means for bodily and adjustably rotating said valve for regulating the pressure and rate of flow of said pressure fluid to said nozzle.

ll. In a spraying device for coating material or the like, in combination, a nozzle provided with coating material and pressure fluid orices, means for controlling the supply of coating material to said nozzle, and a cartridge-like valve assembly disposed within a seat formed in said device for controlling the supply of pressure uid to ,said nozzle, said assembly having a valve chamber therein, a valve seat and associated valve body member within said chamber adapted to divide said chamber into an inlet portion and an outlet portion, means for bodily adjusting said valve assembly for regulating the pressure and rate of flow of said pressure iluid, and means on said valve assembly adapted to cooperate with said valve assembly seat, whereby upon adjustment of said valve assembly the pressure and flow, both into said inlet portion and from said outlet por--l tion of said chamber, is regulated.

12. In a spraying device for coating material or the like, in combination, a nozzle provided with a coating material orifice, an associated propelling uid orifice, and a. supplemental fluid orifice for providing a spray modifying jet, means for controlling the supply of coating material to said nozzle, said device being provided' with a recess, portions of which are respectively in communication with said propelling iuid and said modifying fluid orifices, and a cartridge-like valve assembly disposed within said recess for controlling the supply of pressure uid to said nozzle, said assembly having a valve chamber therein, a valve seat and associated valve body member within said chamber adapted to divide said chamber into an inlet portion and an outlet portion, means for adjusting said valve assembly for regulating the pressure and rate of flow of said pressure uid, and means on said valve assembly adapted to cooperate with said valve assembly recess, whereby upon adjustment of said valve assembly the pressure and rate of flow intosaid inlet portion of saidvalve chamber and from said outlet vportion to both the propelling and modifying Iluid orices of the nozzle is regulated.

13. In a spraying device for coating material or the like, in combination, a nozzle provided with coating material and pressure fluid orifices, means for controlling the supply of coating material to said nozzle, and a valve for controlling the supply of pressure fluid to said nozzle comprising a hollow shell rotatably mounted within said device through which 'all of the pressure uid must pass, means for bodily and adjustably rotating said shell for the purpose .of graduating' the flow and pressure of said uid, and a cut-off valve enclosed within said shell for startingI and stopping the entire flow of pressure fluid.

14. In a spraying device for coating material or the like, in combination, a.nozzle provided with coating material orifices, an associated propelling fluid orice, and a supplemental fluid oriice for providing a spray modifying jet, means for controlling the supply of coatingjmaterial to said nozzle, and a valve for controlling the supply of pressure uid to said nozzle comprising a hollow shell rotatably mounted within said device through which all pressure uid must pass, separate connections between said uid orifices and said shell, means on said shell cooperating with said connections, means for bodily and adjustably rotating said shell for the purposeA of graduating the flow and pressure of said uidto both said propelling and modifying fluid orices, and a cut-oii' valve enclosed within said shell for starting and stopping the entire flow of pressure uid.

15. In a. spraying device for coating material or the like, in combination, a nozzle provided with coating material and pressure fluid orices, means for controlling the supply of coating material to said nozzle, and a valve for controlling the supply of pressure fluid to said nozzle comprising a unitary valve assembly rotatably mounted within said device through which all of the pressure iiuid must pass, means for bodily and adjustably rotating said assembly as a ico iis l unit for the purpose f graduating the flow and pressure of said fluid, and reciprocating means within said assembly i'or opening up and cutting oi! the iiow o! pressure iluid, andI means for restraining said unitary assembly against reciprocation.

16. In a spraying device for coating material or the like, vin combination, a nozzle provided with coating material and pressure uid orices, means for controlling the supply of coating material to said nozzle, and a valve tor controlling the supply of pressure uid to said nozzle comprising a unitary valve assembly rotatably mounted within los 

